package com.jqing.lib.file;

import java.io.*;

/**
 * Created by chshqiang on 15-6-24.
 * 文件流操作类
 */
public class WriteFileHelper {
    /**
     * A方法追加文件：使用RandomAccessFile
     */
    public static void appendMethodA(String fileName, String content) {
        try {
            // 打开一个随机访问文件流，按读写方式
            RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw");
            // 文件长度，字节数
            long fileLength = randomFile.length();
            //将写文件指针移到文件尾。
            randomFile.seek(fileLength);
            randomFile.writeBytes(content);
            randomFile.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * B方法追加文件：使用FileWriter
     */
    public static void appendMethodB(String fileName, String content) {
        try {
            //打开一个写文件器，构造函数中的第二个参数true表示以追加形式写文件
            FileWriter writer = new FileWriter(fileName, true);
            writer.write(content);
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void cleanFile(String fileName) {
        try {
            File file = new File(fileName);
            if (file.exists()) {
                FileWriter fileWriter = new FileWriter(fileName, false);
                fileWriter.write("");
                fileWriter.close();
                file.deleteOnExit();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
